Prokaryotes + Viruses

• Nucleus

  Prokaryotes - No Nucleus

  Eukaryotes - Nucleus Present
• DNA

  Prokaryotes - Plasmid DNA

  Eukaryotes - Multiple chromosomes
• Prokaryotes - Only unicellular

  Eukaryotes - Multicellular or Unicellular
• Ribosomes

  Prokaryotes - Smaller ribosomes

  Eukaryotes - Larger ribosomes
• Size

  Prokaryotes - Around 1um-10um

  Eukaryotes - Around 10um-100um
• Cell walls

  Prokaryotes - Cell walls present as peptidoglycan

  Eukaryotes - Cell walls only present in fungi as chitin and also in plants
• Examples

  Prokaryotes - Cyanobacteria, used for photosynthesis

  Eukaryotes - Stem cells in animals, meristem cells in plants
• UM – Micrometre

  NM - Nanometre

  1UM  = 1000NM
• Viruses are non-living and cannot reproduce on their own, they must infect a living cell to reproduce, known as a host cell.
• Viruses are much smaller than bacteria, measuring around 20-300NM
• Viruses contain nucleic acids which are contained in protein coats called capsids.
• The lipid envelope or capsid in a virus have attachment proteins which enable the virus to identify and attach to a cell.
• During infection, the virus enters the host cell by attaching itself to receptors on the surface of the cell membrane using its attachment proteins.